Yarn feeder for a knitting machine

ABSTRACT

A yarn feeder for a knitting machine comprises a rotatable cylinder having an outer surface possessing a high coefficient of friction. A yarn guide is mounted for rotation on a common axis with the cylinder and has fingers which engage yarn. A motor rotates the yarn guide between a position in which the yarn is engaged by the cylinder and fed to the knitting machine and a position in which the yarn is disengaged from the cylinder.

United States Patent Delair et al.

[54] YARN FEEDER FOR A KNITTING MACHINE [72] Inventors: Jean-Paul Delair, 40 Boulevard Jules Guesde; Raisin: Jean-pierre, 15 rue Auguste Renoir, both of IO Troyes; Eugene Voisin, l0 Souligny, all of France [22] Filed: March 5, 1971 [21] Appl. No.: 121,440

Related U.S. Application Data [63] Continuation-impart of Ser. No. 82l,792, May

5, 1969, abandoned.

[30] Foreign Application Priority Data May 8, 1968 France ..68l50975 [52] U.S. Cl. ..226/l14, 226/174, 66/132 [5 1] Int. Cl. ..B65h 17/42 [58] Field of Search ..226/34, 35, I68, 195, 114, 226/113, I74; 66/132 [56] References Cited UNITED STATES PATENTS 2,917,914 12/1959 Shortland ..66/l32 1 1 Oct. 24, 1972 FOREIGN PATENTS OR APPLICATIONS 8/1963 Great Britain ..66/l 32 942,347 ll/l963 GreatBritain ..66/l32 Primary Examiner-Richard A. Schacher Assistant Examiner-Gene A.-Church Attorney-Harpman & Harpman [57] ABSTRACT A yarn feeder for a knitting machine comprises a v rotatable cylinder having an outer surface possessing a high'coefficient of friction. A yarn guide is mounted for rotation on a common axis with the cylinder and has fingers which engage yarn. A motor rotates the I yarn 'guide between a position in which the yarn is engaged by the cylinder and fed to the knitting machine and a position in which the yarn is disengaged from the cylinder.

6 Claims, 7 Drawing Figures YARN FEEDER FOR A KNITTING MACHINE This is a continuation-in-part of application Ser. No. 821,792 filed May 5, 1969 now abandoned.

The present invention relates to yarn feeders for knitting machines.

In the case of one known yarn feeder, there is a control device comprising a double lever one of whose ends carries an eye through which the yarn passes and whose other end acts on a yarn guide so that the lever rotates about its axis in such a manner as to wind more of the yarn on the feed cylinder of the yarn feeder or to disengage a certain amount of yarn from the feed cylinder as a function of the yarn tension between the yarn feeder and the knitting machine, in order to keep the tension of the yarn delivered to the needles constant.

Such a yarn feeder, from its design, does not lend itself to a rapid removal and threading of the yarn on to the yarn feeder.

In another known yarn feeder similar to the one described above, two rotatable yarn guides are associated with a feed cylinder. Each of the pivotable yarn guides is mounted so as to rotate about a pivot parallel to the axis of the cylinderand is placed close to this axis. When the pivotable yarn guides are rotated in opposite directions, the yarn can be placed in contact with a little more of the half of the periphery of the feed cylinder. During the application of the yarn on the feed cylinder of the yarn feeder, at least the output end yarn guide located between the cylinder and the knitting machine introduces a stray tension in the yarn, with the result that faults or irregularities appear in the loops of the knitted fabric.

Knitting on seamless stocking machines or on ribbedtop plain fabric machines generally involves the production of articles or of plain fabrics having predetermined dimensions. It is therefore important for all the articles or all the plain fabrics in a batch to have the same dimensions irrespective of the yarn used, the color of the yarn and the knitting machines used in order to facilitate matching. It is therefore necessary for the products obtained to display the same characteristics from the point of view of their dimensions. For this purpose it is necessary that the length of yarn taken by the knitting machine to form each loop is controlled especially during the knitting of, for example, the leg part of stockings.

Also, it is essential to correct the variations due to the knitting machine and to control the rate of formation of the loops and also the tension during feeding of the yarn.

The present invention has as its object the remedying of the above disadvantages and the providing of a yarn feeder for at least one yarn and which allows a constant quantity of chosen yarn to be fed to each needle at a given instant under constant tension and to stop or restart delivery of yarn without having to stop the rotation of the yarn feeder and without introducing stray tensions in the yarn between the knitting machine and the yarn feeder during these'operations.

According therefore, to the present invention there is provided a yarn feeder. for a knitting machine, of the type comprising at least one feed cylinder coated by a friction layer intended to come into contact with at least one yarn; a motor connected to the feed cylinder and imparting to this latter a continuous movement of rotation about its axis; a pivotable yarn guide mounted idly on the axis of rotation of the feed cylinder and arranged on the side of this cylinder so as to be able to pivot about this axis independently of the rotation of said cylinder, said pivotable yarn guide comprising at the end opposite that mounted on the axis of the feed cylinder two fingers between which the yarn passes, said fingers being parallel with the axis of the feed cylinder and located above and opposite the envelope of the feed cylinder; a fractional horse-power motor capable of rotating in the two directions of rotation and cooperating with the yarn guide so as to cause it to pivot between two extreme positions about the feed cylinder in order to apply the yarn to the feed cylinder or to bring it out of contact with this latter, the kinematic connection between the fractional horsepowermotor and the yarn guide being arranged so that the pivoting of the yarn guide from the position where the yarn is out of contact with the feed cylinder, is effected in the direction opposite the direction of rotation of the feed cylinder, and a yarn tensioning element mounted upstream of the feed cylinder and a fixed yarn guide mounted downstream of this latter, said yarn tensioning element and said yarn guide being traversed by the yarn and located in a plane located outside of the feed cylinder.

The invention is illustrated, merely by way of example, in the accompanying drawings, in which:

FIG. 1 is a schematic representation of the knitting machine equipped with a yarn feeder according to the present invention,

FIG. 2 is a side view of the yarn feeder shown in FIG. 1, with the yarn in the disengaged position,

FIG. 3 is a side view of the yarn feeder shown in FIG. 1, with the yarn in the engaged position,

FIG. 4 is a side view of another yarn feeder according to the present invention, with the yarn in the disengaged position,

FIG. 5 is a view similar to that of FIG. 4 with the yarn in the engaged position,

FIG. 6 is a front view of an axially elongated yarn feeder for a plurality of yarns, and

' FIG. 7 is a plan view of the yarn feeder shown in FIG.

The knitting machine is made up of a cylinder 1 equipped with a plurality of latch needles 2 and set in rotation by a motor (not shown) via the intermediary of a toothed gear 3. A variable speed device 4, driven by a motor (not shown), is provided with an output shaft 5 that normally rotates continually at a constant speed and is rigidly connected with a drive shaft 6a of a feeder 6 having a frame or cylinder 6b covered with a layer having a high coefficient of friction. An electric fractional horse-power motor 7 capable of rotation in either direction rotates a pivotable yarn guide 8 rigidly connected to a reducing gear mechanism 9 consisting of two gears 9a and 9b, the latter being mounted idly on the drive shaft 6a of the feeder 6 and supporting the pivotable yarn guide 8. The gears 9a and 9b comprise two toothed wheels 9a and 9b cooperating with one another. The toothed wheel 9a is splined to the driven shaft of the motor 7 whilst the toothed wheel 9b is mounted to rotate freely on the axis or drive shaft 6a of the feed cylinder 6b. The yarn guide 8 is rigidly fixed to a side face of the toothed wheel 9b, this side being adjacent to the feed cylinder 6b. Yarn 12 from a bobbin (not shown) passes over two fixed yarn guides 10a, 10b

" disposed on the path of the yarn 12 above the feed cylinder 6b and on both sides of said feed cylinder 6b and between two fingers l 1 of the pivotable yarn guide 8 and to a further fixed yarn guide 100 before being taken up by the needles 2. The two fingers 11 of the pivotable yarn guide 8 are provided at the end opposite that mounted on the shaft or axis 6a of the feed cylinder 6b, said fingers being parallel with the axis 6a of the feed cylinder 6b and located above and opposite the envelope of the feed cylinder. The fingers 1 1 define an orifice which receives the yarn 12. As one can see, on FIGS. 2 and 3, and also on FIGS. 4 and 5 described further, the two fixed yarn guides a, 10b are disposed upstream and downstream of the yarn feeder 6 so as to define a horizontal level or plane above and outside feed cylinder. When the pivotable yarn guide or guides 8 occupies (occupy) its (their) upper extreme position in which the yam- 12 is disengaged from the corresponding feed cylinder 6b of the yarn' feeder 6, the two fingers 11 of the-pivotable yarn guide 8 are situated on both sides of the level or plane passing through the two fixed yarn guides 10a and 10b. The yarn is applied to the periphery or envelope of the cylinder 6b by a pivoting of the pivotable yarn guide 8 in a sense opposite to the sense of rotation of the cylinder 6b. The motor 7 is for example a well known reversible D-C motor having one induced winding whose polarization element 18. This tension prevents-slip of the elastic yarn on the cylinder 13. However, when the yarn is disengaged from the cylinder 13, because no tension is needed for the next knitting operation, the tension produced by the tensioning element 18 may then be too high to allow the knitting machine to operate satisfactorily.

This disadvantage appearing when using elastic yarns has been remedied by the use of cylinder 14 on the yarn guides 8, the tension produced by tensioning elemay be changed so as to reverse the direction of rotation of the motor. A starting switch, two limit switches and .a reversing switch are provided in the electrical feed circuit of the motor 7 and may be actuated manually or automatically. Therefore a cam may be suitably mounted on the cylinder 1 of the knitting machine so as to be able to actuate reversing and starting switch in the desired moment. The rotation of the pivotable yarn guide 8 from one end position to the other in one and the other direction of rotation on an arc path of about 180 is limited by one of the two limit switches (not shown) provided in the electrical feed circuit of the motor 7, one or the other switch being actuated manually or by a stop unitary with the yarn guide 8 or one of the kinematic means connection between the yarn guide 8 and the motor 7.

According to a different embodiment of the invention shown in FIGS. 4 and 5 the yarn feeder 6 has two cylinders 13 and 14 which are mounted in series on two shafts 13a, 14a respectively. On each shaft 13a, 14a is mounted to rotate freely the toothed wheel 9b to which the pivotable yarn guide 8 is fixed rigidly, the cylinder 14 preferably having a diameter that is smaller than that of cylinder 13 but set to rotate at the same angular speed. Either or both of the drive shafts 13a, 14a of the cylinders 13 or 14 are connected to the variable speed device 4.

It will be appreciated that it is possible to provide two feed cylinders of the same diameter and to drive them at different speeds of rotation. Such an arrangement eliminates slip of the yarn 12 on cylinder 13 when elastic yarn has to be fed with predetermined tension, and speed to the knitting machine. While the yarn 12 is engaged by the cylinder 13, it is necessary to impart a tension to it on the input side, i.e., the side adjacent the fixed yarn guide 10a, this is achieved by a tensioning ment 18 on the yarn is sufficiently high for engaging the yarn 12 on the cylinder 14 without slip, as the linear peripheral speed of cylinder 14 is slightly less than that of cylinder 13.

The mode of functioning of the yarn feeder according to the present invention is as follows: I

During the period'when the yarn 12 need not be engaged by the feeder 6,.it is simply guided between the fingers ll'of the pivotable yarn guide 8 in its upper end position and held under slight tension by the tensioning element 18.

When the yarn 12 is to be engaged by the yarn feeder 6 and fed to the knitting machine the fractional horse power motor 7 controls the reducing gear mechanism 9 which pivots the gear 9b of the pivotable yarn guide 8 in a direction opposite to the direction of rotation of the feed cylinder 6b or feed cylinders 13, 14 and moves the yarn guide 8 into a position in which the yarn is wound in a large arc on to the cylinder 6b or the cylinders 13, 14 before being fed to the needles 2. The disengaging of the yarn 12 from feed cylinder 6b is controlled in like manner by the fractional horse power motor 7 which then turns in the reverse sense causing the pivotable yam guide 8 to return to its upper end position shown in FIGS. 2 and 4.

Thus each engaging or disengaging of the yarn 12 by the continuously rotating yarn feeder 6 is preceded or followed by a short period of working of the yarn without the aid of the yarn feeder 6. During this period the tension in the yarn 12, which is imparted by a tensioning element 18 which maybe of any known type and which may be located on the input side, i.e., upstream of yarn feeder 6, is of small value for example is about 1 gm. for 15-denier 6-6 nylon monofil yarn.

The functioning of the two-cylinder yarn feeder of FIGS.4 and 5 is identical to that described with regard to the yarn feeder of FIGS. 1 to 3, except that the pivotable yarn guide 8 of cylinder 14 is operated a short period after or before the operation of the pivotable yarn guide 8 of cylinder 13, following which the yarn of the yarn feeder is engaged or disengaged. The yarn will pass in the same way over the two cylinders, each yarn being guided successively by the pivotable yarn guide 8 of cylinder 14 and by the pivotable yarn guide 8 of cylinder 13, each pivotable yarn guide being mounted to rotate freely on the shaft of the respective cylinder and capable of being actuated by an associated fractional horse power motor in the same manner as the yarn guide 8 of FIGS. 1 to 3.

For knitting seamless stocking one generally uses a machine with multiple cam blocks (now shown). According to the invention, each of the yarns fed to each cam block for forming the various parts of the stocking such as leg and foot passes over the same yarn feeder 6 and in the above-described manner. This is accomplished by simply axially elongating the feed cylinder 6b as well as the two fingers 11 of the yarn guide 8 and to provide, upstream and downstream of the cylinder 6b a corresponding number of tensioning elements 18 and of fixed yarn guides 10a on the one hand, and of fixed yarn guides 10b on the other hand as shown in FIGS. 6 and 7. If a yarn feeder 6 comprising two feed cylinders 13 and 14 and a pivotable yarn guide 8 on the driving shaft of each cylinder 13 and 14, it is also advantageous, but not absolutely necessary, to provide between the upstream side of the feed cylinder 14 and the tensioning elements 18 a corresponding number of fixed yarn guides 10a.

The functioning of the yarn feeder of FIGS. 6 and 7 is identical to that described with regard to the yarn feeder of FIGS. 1 to 3, except that in this case it applies to or disengages from the feed cylinder simultaneously a plurality of yarns.

What is claimed is:

1. Yarn feeder for a knitting machine, of the type comprising at least one feed cylinder coated by a friction layer intended to come into contact with at least one yarn; a motor connected to the feed cylinder and imparting to this latter a continuous movement of rotation about its axis; a pivotable yarn guide mounted idly on the axis of rotation of the feed cylinder and arranged on the side of this cylinder so as to be able to pivot about this axis independently of the rotation of said cylinder, said pivotable yarn guide comprising at the end opposite that mounted on the axis of the feed cylinder two fingers between which the yarn passes, said fingers being parallel with the axis of the feed cylinder and located above and opposite the envelope of the feed cylinder; a fractional horse power motor capable of rotating in the two directions of rotation and cooperating with the yarn guide so as to cause it to pivot between two extreme positions about the feed cylinder in order to apply the yarn to the feed cylinder or to bring it out of contact with this latter, the kinematic connection between the fractional horse-powermotor and the yarn guide being arranged so that the pivoting of the yarn guide from the position where the yarn is out of contact with the feed cylinder, is effected in the direction opposite the direction of rotation of the feed cylinder, and a yarn tensioning element mounted upstream of the feed cylinder and a fixed yarn guide mounted downstream of this latter, said yarn tensioning element and said yarn guide being traversed by the yarn and located in a plane located outside of the feed cylinder.

2. Yarn feeder according to claim 1 comprising in addition to the first feed cylinder, its drive motor, its mobile yarn guide and the fractional horse-power motor for said yarn guide, a second feed cylinder arranged parallel to the axis of the first feed cylinder between the input side of the latter and the output side of the tensioning element, and associated in the same manner as the first feed cylinder with a drive motor, with a drive motor, with a second pivotable yarn guide d wi a fractio al h sewer motor coo eratin ll th sai second p ivota le y n guide for said secong feed cylinder, the yarn passing through the two yarn guides.

3. Yarn feeder according to claim 2, in which the two feed cylinders are connected in rotation with a single drive motor and in which a speed variator is interposed between at least one of the two feed cylinders and the single drive motor, so that the feed cylinder connected to the single drive motor by means of the speed variator may be driven at rotational speeds different from that of the feed cylinder directly connected to the single drive motor.

4. Yarn feeder according to claim 2, in which the diameter of the first feed cylinders is different from that of the second feed cylinder.

5. Yarn feeder according to claim 1, in which the fingers of the pivotable yarn guide define at one end an opening for introducing the yarn therein.

6. Yarn feeder according to claim 1, in which a second fixed yarn guide is arranged near the downstream side of the yarn tensioning element and in the same plane defined by this latter and the first fixed yarn guide. 

1. Yarn feeder for a knitting machine, of the type comprising at least one feed cylinder coated by a friction layer intended to come into contact with at least one yarn; a motor connected to the feed cylinder and imparting to this latter a continuous movement of rotation about its axis; a pivotable yarn guide mounted idly on the axis of rotation of the feed cylinder and arranged on the side of this cylinder so as to be able to pivot about this axis independently of the rotation of said cylinder, said pivotable yarn guide comprising at the end opposite that mounted on the axis of the feed cylinder two fingers between which the yarn passes, said fingers being parallel with the axis of the feed cylinder and located above and opposite the envelope of the feed cylinder; a fractional horse power motor capable of rotating in the two directions of rotation and cooperating with the yarn guide so as to cause it to pivot between two extreme positions about the feed cylinder in order to apply the yarn to the feed cylinder or to bring it out of contact with this latter, the kinematic connection between the fractional horse-power-motor and the yarn guide being arranged so that the pivoting of the yarn guide from the position where the yarn is out of contact with the feed cylinder, is effected in the direction opposite the direction of rotation of the feed cylinder, and a yarn tensioning element mounted upstream of the feed cylinder and a fixed yarn guide mounted downstream of this latter, said yarn tensioning element and said yarn guide being traversed by the yarn and located in a plane located outside of the feed cylinder.
 2. Yarn feeder according to claim 1 comprising in addition to the first feed cylinder, its drive motor, its mobile yarn guide and the fractional horse-power motor for said yarn guide, a second feed cylinder arranged parallel to the axis of the first feed cylinder between the input side of the latter and the output side of the tensioning element, and associated in the same manner as the first feed cylinder with a drive motor, with a drive motor, with a second pivotable yarn guide and with a fractional horse-power motor cooperating with said second pivotable yarn guide for said second feed cylinder, the yarn passing through the two yarn guides.
 3. Yarn feeder according to claim 2, in which the two feed cylinders are connected in rotation with a single drive motor and in which a speed variator is interposed between at least one of the two feed cylinders and the single drive motor, so that the feed cylinder connected to the single drive motor by means of the speed variator may be driven at rotational speeds different from that of the feed cylinder directly connected to the single drive motor.
 4. Yarn feeder according to claim 2, in which the diameter of the first feed cylinders is different from that of the second feed cylinder.
 5. Yarn feeder according to claim 1, in which the fingers of the pivotable yarn guide define at one end an opening for introducing the yarn therein.
 6. Yarn feeder according to claim 1, in which a second fixed yarn guide is arranged near the downstream side of the yarn tensioning element and in the same plane defined by this latter and the first fixed yarn guide. 